Nigel Farage's UKIP sent tremors through the political system in the European elections on Sunday night after emerging as the big victor.
The party now has 23 seats in the European Parliament with some results still to come in.
Ukip effectively became the first party, other than Labour or the Conservatives to win a national election in over 100 years.
Mr Farage hailed the result, which saw the Liberal Democrat vote collapse, as historic and said Ukip was now the 'third force' in British politics.
The party looked set to end up with 24 MEPs.
In the South West constituency, which includes Dorset, Ukip polled 484,184 votes with the Conservatives racking up 433,191.
The six SW seats up for grabs in the European were won by Ukip (two), Conservatives (two), Labour and the Green Party.
The Liberal Democrat vote slumped and long serving MEP Sir Graham Watson lost his seat.
Sir Graham Watson
One of the Conservative victors, Ashley Fox, said the voters "have sent a message that the relationship with the EU had to change."
The new MEP line-up is Ashley Fox and Julie Girling (Conservatives), William Dartmouth and Julia Reid (UKIP), Claire Moody (Labour), Molly Scott Cato (Green).
Vikki Slade, leading Liberal Democrat councillor in Poole and prospective parliamentary candidate for Mid Dorset said she was "totally gutted" by the result.
"We have to recognise people's concern about Europe and immigration and deal with them. This is long term, not just a protest and we ignore it at our peril."
Leading Poole Lib Dem Cllr Mike Brooke said he did not think Nick Clegg shouls resign but needed "to look at his advisers. I think I am entitled to criticise."
Bournemouth East MP, Tobias Ellwood, said the results showed the British people wanted "a more robust approach" over immigration and Europe.
Sir Graham took to the stage to say it has been 'an honour and a privilege' to serve the South West over two decades.
There were big cheers from Labour and Green activists as both parties secured one seat each at the count in Poole's Civic Centre. The declaration was made at 11.35pm.
Julie Girling, Conservative
The night's results will pile further pressure on the established Westminster parties to find ways to win back supporters.
Nick Clegg - who has acknowledged the Liberal Democrats could lose all of their 11 MEPs - is facing MPs' questions over his leadership and calls to quit from activists including general election candidates.
Mr Farage predicted that Mr Clegg would be ousted before next year's general election.
He said: "Nick Clegg's position clearly is very vulnerable indeed. I'd be very surprised if he led the Lib Dems into the next election."
David Cameron has been urged by influential Tory MP David Davis to bring forward his promised EU referendum by a year to 2016 in a bid to persuade defectors to Ukip he is serious.
He blamed Ukip's strong showing on widespread disillusionment with the EU.
European votes were cast on Thursday at the same time as local elections in which Ukip gained 128 seats and made serious inroads into Conservative, Labour and Liberal Democrat support.
The number of votes cast for each party in the South West was:
An Independence From Europe - 23,169
British National Party - 10,910
Conservative Party - 433,151
English Democrats Party - 15,081
Green Party - 166,447
Labour Party - 206,124
Liberal Democrats - 160,376
United Kingdom Independence Party - 484,184
The six elected Members of the European Parliament are:
1 - William Dartmouth, United Kingdom Independence Party
2 - Ashley Peter Fox, Conservative Party
3 - Julia Reid, United Kingdom Independence Party
4 - Julia McCulloch Girling, Conservative Party
5 - Claire Miranda Moody, Labour Party
6 - Molly Scott Cato, Green Party
The overall turnout for the South West region was 37.03 per cent compared to 38.87 per cent in 2009.
Follow live updates from Poole Civic Centre below